Precision positioning can be accomplished with three degree-of-freedom (3-DOF) positioning stages. One type of positioning stage has a separate sliding joint for each DOF, which results in a stack of four plates allowing one DOF motion between any two plates. In addition, each joint can have a dovetail slide or other rail joint. The joints are commonly adjusted using a screw drive in the direction of the desired motion, resulting in the screws being orthogonal to each other. Locking the joints can be implemented, and play in the joints eliminated, by adding a locking screw to apply a side load from a fixed part of the joint onto a moving part of the joint for each stage. However, such a locking screw relies on friction in the slide to be high enough to prevent slippage.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.